零价铁还原和过硫酸盐氧化联合降解水中硝基苯

Degradation of nitrobenzene by the combined system of zero-valent iron reduction and persulfate oxidation

将零价铁(Fe0)的还原和过硫酸盐(persulfate,PS)的高级氧化技术结合用于水中难降解有机污染物硝基苯的去除.研究结果表明,Fe0在常温常压下可将硝基苯还原生成苯胺,随着Fe0投加量的增加,硝基苯还原为苯胺的速率逐渐增大.PS本身对硝基苯氧化作用不明显,但在Fe0与PS二者联合体系中,硝基苯和苯胺同时被去除,而且随着PS投加量的增加二者被去除的速度也随之增加.在Fe0还原和PS氧化联合处理硝基苯的体系中可能存在两个过程,一是Fe0还原硝基苯产生苯胺和二价铁离子Fe2+,二是Fe2+催化PS产生强氧化性的硫酸根自由基将苯胺氧化降解.

The degradation of nitrobenzene by the combined system of zero-valent iron reduction and persulfate oxidation was studied in this paper.At ambient temperature and pressure,zero-valent iron（Fe0） was used to decompose nitrobenzene,and aniline was formed accordingly.Experimental results showed that increasing Fe0 dosage accelerated nitrobenzene removal rate.Persulfate（PS） alone did not degradate nitrobenzene.However,there existed a synergistic effect in the combined system of Fe0 and PS.With the increase of PS dosage,the removal of nitrobenzene and aniline was accelerated.There existed two processes in the combined system.Firstly,nitrobenzene was decomposed by Fe0 to produce aniline and Fe2＋.And secondly,the produced aniline was oxidized by the sulfate free radical SO·-4,which was generated from Fe2＋ catalyzing PS decomposition.